Jake Goulding

This RFC is *exactly* what I want, and I've even created a lot of the same structure myself by hand to get something similar in today's Rust. I have types...

@pnkfelix I'd like to request your assistance in figuring out what next steps I need to make to get this merged.

Addressed @estebank's concerns in [this force push](https://github.com/rust-lang/rust/compare/50595a0178c08fe2cb65e1980cc45ae9f0066057..c0652dfc44dd6d5f8ab288d56638ef2e45adf2d8).

Force pushed to [try and fix the build](https://github.com/rust-lang/rust/compare/c0652dfc44dd6d5f8ab288d56638ef2e45adf2d8..1658456cebb0b7fef82a182f61be8819ecf7bba1) and then another force push to [address the conflict](https://github.com/rust-lang/rust/compare/1658456cebb0b7fef82a182f61be8819ecf7bba1..6f3941caa177b4337b7c0ccf9ef62001f2162370).

[Another force push](6fcefa3ee1a2b43a1c816dd8c903fd78be1a7da1) to address test failures.

With SIMD stabilizing in 1.27, [Jetscii will be available on stable](https://users.rust-lang.org/t/jetscii-now-works-with-future-stable-rust-1-27-0/17426), but its `Pattern` support won't — I never expected that SIMD would arrive before this! 😇

> that criterion is spawning a large set of threads The code in question is not using criterion (the benchmarks are in a separate child crate). This code _is_ using...

> do you see that message? I do not ``` MIRIFLAGS='-Zmiri-disable-isolation -Zmiri-disable-stacked-borrows -Zmiri-disable-data-race-detector' \ CARGO_TARGET_DIR=target/miri \ cargo miri test -- --nocapture Compiling sxd-string-slab v0.1.0 (/Users/shep/Projects/sxd/string-slab) Finished test [unoptimized + debuginfo]...

Perhaps it's been fixed in Miri already? I still see it with Miri 1cf1a2e4: Run log ``` /tmp % git clone https://github.com/shepmaster/sxd-string-slab/ Cloning into 'sxd-string-slab'... remote: Enumerating objects: 67, done....

> the macro-expanded impl of `iter::Sum` ends up looking like this Should it short-circuit?